Macroalgae across environmental gradients : tools for managing rocky coastal areas of the northern Baltic Sea

Macroalgae are the main primary producers of the temperate rocky shores providing a three-dimensional habitat, food and nursery grounds for many other species. During the past decades, the state of the coastal waters has deteriorated due to increasing human pressures, resulting in dramatic changes in coastal ecosystems, including macroalgal communities. To reverse the deterioration of the European seas, the EU has adopted the Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD), aiming at improved status of the coastal waters and the marine environment. Further, the Habitats Directive (HD) calls for the protection of important habitats and species (many of which are marine) and the Maritime Spatial Planning Directive for sustainability in the use of resources and human activities at sea and by the coasts. To efficiently protect important marine habitats and communities, we need knowledge on their spatial distribution. Ecological knowledge is also needed to assess the status of the marine areas by involving biological indicators, as required by the WFD and the MSFD; knowledge on how biota changes with human-induced pressures is essential, but to reliably assess change, we need also to know how biotic communities vary over natural environmental gradients. This is especially important in sea areas such as the Baltic Sea, where the natural environmental gradients create substantial differences in biota between areas. In this thesis, I studied the variation occurring in macroalgal communities across the environmental gradients of the northern Baltic Sea, including eutrophication induced changes. The aim was to produce knowledge to support the reliable use of macroalgae as indicators of ecological status of the marine areas and to test practical metrics that could potentially be used in status assessments. Further, the aim was to develop a methodology for mapping the HD Annex I habitat reefs, using the best available data on geology and bathymetry. The results showed that the large-scale variation in the macroalgal community composition of the northern Baltic Sea is largely driven by salinity and exposure. Exposure is important also on smaller spatial scales, affecting species occurrence, community structure and depth penetration of algae. Consequently, the natural variability complicates the use of macroalgae as indicators of human-induced changes. Of the studied indicators, the number of perennial algal species, the perennial cover, the fraction of annual algae, and the lower limit of occurrence of red and brown perennial algae showed potential as usable indicators of ecological status. However, the cumulated cover of algae, commonly used as an indicator in the fully marine environments, showed low responses to eutrophication in the area. Although the mere occurrence of perennial algae did not show clear indicator potential, a distinct discrepancy in the occurrence of bladderwrack, Fucus vesiculosus, was found between two areas with differing eutrophication history, the Bothnian Sea and the Archipelago Sea. The absence of Fucus from many potential sites in the outer Archipelago Sea is likely due to its inability to recover from its disappearance from the area 30-40 years ago, highlighting the importance of past events in macroalgal occurrence. The methodology presented for mapping the potential distribution and the ecological value of reefs showed, that relatively high accuracy in mapping can be achieved by combining existing available data, and the maps produced serve as valuable background information for more detailed surveys. Taken together, the results of the theses contribute significantly to the knowledge on macroalgal communities of the northern Baltic Sea that can be directly applied in various management contexts.

Corticolous green algae from tropical forest remnants in the northwest region of São Paulo State, Brazil

The algae inhabit a wide variety of terrestrial environments and substrates; however the taxonomic knowledge for tropical regions is still scarce. This survey was conducted in ten forest remnants in São Paulo State where visible growths of algae and bryophytes were collected and studied for the main algal components of the communities. Results reveal the occurrence of nine species of green algae, distributed through the class Trebouxiophyceae (one species), Charophyceae (one species) and Ulvophyceae (seven species). Desmococcus olivaceus (Persoon ex Archerson) J. R. Laundon and Printzina effusa (Krempelhüber) Thompson & Wujek are new records for Brazil. The most frequent organisms found in the areas pertain to Trentepohliales that is mainly represented by Trentepohlia species. On the basis of results found, it is recommended that such communities receive more attention in future investigations to improve the knowledge about this important group of primary producers.

Los newagers: el efecto colibrí. Artífices de menús especializados, tejedores de circuitos en la red, y polinizadores de culturas híbridas

En este artículo se describe la trayectoria de búsqueda espiritual de un agente nodal en la red espiritual alternativa comúnmente conocida como New Age para atender el impacto de su trayectoria en la hibridación de una espiritualidad neoindia. Se proponen tres procesos a tenerse en cuenta para una metodología del estudio del impacto de hibridación cultural que genera el New Age: 1) Su condición de diseñador de menús creyentes individualizados hechos con retazos de distintas tradiciones religiosas (Champion y Hervieu-Lèger 1990); 2) su agencia como “agente nodal” para tejer articulaciones, alianzas y conexiones en la red: entre otros agentes nodos, entre diversos circuitos y otros campos sociales especializados; y 3) su competencia de “polinizador” (Soares 2009) de culturas y religiones. El argumento de este trabajo destaca que los buscadores espirituales en su andar no sólo recogen fragmentos culturales de distintas tradiciones para armar menús personalizados de creencias, sino que además son transmisores de significados que contribuyen a hibridar las culturas por donde van pasando. Muchas de las cuales coinciden con comunidades étnicas valoradas por su relación con la naturaleza, su ancestralidad y su exotismo a los ojos de los occidentales.

Correlation of discocyte frequency and ATP concentration in preserved blood: A morphological indicator of red blood cell viability

Red blood cells (RBC) are viable if kept in an adequate preservative solution, although gradual changes in morphology and metabolism may occur. There is a gradual decrease in adenosine-5'-triphosphate (ATP) concentration, pH, glucose consumption, and enzyme activity during preservation. The normal discocyte shapes are initially replaced by echinocytes and stomatocytes and, at final stages, by spherocytes, the last step before splenic sequestration. Post-transfusional survival has been correlated with the ATP concentration. RBC preserved in ADSOL, a solution containing adenine, dextrose, sodium chloride, and mannitol, are viable for transfusion for up to 6 weeks. Erythrocytes from 10 blood units taken from healthy adult donors were preserved for 12 weeks in ADSOL at 4oC. We now report a significant correlation (r2 = 0.98) between the percentage of discocytes (89 to 7%) and ATP (100 to 10%) concentration in ADSOL-preserved RBC. The results suggest that the percent of discocyte shapes used as an indicator of ATP concentration may be a useful indicator for quality control of RBC viability in centers which have limited assay facilities.

Regulation of the expression of NADP-malic enzyme by UV-B, red and far-red light in maize seedlings

The induction of nicotinamide adenine dinucleotide phosphate-malic enzyme (NADP-ME) in etiolated maize (Zea mays) seedlings by UV-B and UV-A radiation, and different levels of photosynthetically active radiation (PAR, 400-700 nm) was investigated by measuring changes in activity, protein quantity and RNA levels as a function of intensity and duration of exposure to the different radiations. Under low levels of PAR, exposure to UV-B radiation but not UV-A radiation for 6 to 24 h caused a marked increase in the enzyme levels similar to that observed under high PAR in the absence of UV-B. UV-B treatment of green leaves following a 12-h dark period also caused an increase in NADP-ME expression. Exposure to UV-B radiation for only 5 min resulted in a rapid increase of the enzyme, followed by a more gradual rise with longer exposure up to 6 h. Low levels of red light for 5 min or 6 h were also effective in inducing NADP-ME activity equivalent to that obtained with UV-B radiation. A 5-min exposure to far-red light following UV-B or red light treatment reversed the induction of NADP-ME, and this effect could be eliminated by further treatment with UV-B or red light. These results indicate that physiological levels of UV-B radiation can have a positive effect on the induction of this photosynthetic enzyme. The reducing power and pyruvate generated by the activity of NADP-ME may be used for respiration, in cellular repair processes and as substrates for fatty acid synthesis required for membrane repair.

The calcium-dependent protease of Loxosceles gaucho venom acts preferentially upon red cell band 3 transmembrane protein

Eighty micrograms red blood cell (RBC) ghosts from patients who had previously exhibited the cutaneous form of loxoscelism (presenting localized dermonecrosis) and the viscerocutaneous form of loxoscelism (presenting dermonecrosis, hemoglobinuria, hematuria, and jaundice) and from controls were incubated with 2.5 µg crude Loxosceles gaucho venom in 5 mM phosphate buffer, pH 7.4, at 37ºC. Among all membrane proteins, quantitative proteolysis of the important integral transmembrane protein 3 increased with venom dose and with incubation time from 30 to 120 min, as demonstrated by gel densitometry. Similar quantitative data were obtained for RBC ghosts from patients and from control subjects, a fact that argues against the possibility of genetic factors favoring the hemolytic viscerocutaneous form. These data suggest that the clinical forms may be different types of the same disease, with the viscerocutaneous form being the result of large amounts of intravascularly injected venom and the superficial form being the result of in situ venom action. Since protein 3 is a housekeeping integral membrane protein, whose genetic deficiency leads to hemolytic anemia, it is reasonable to relate it to the hemolysis which occurs in the viscerocutaneous form of loxoscelism. The venom protease responsible for the process was not inhibited after 120-min incubation by 0.2 mM paramethylsulfonyl fluoride or by 0.2 mM N-ethylmaleimide but was inhibited by 25 mM ethylenediaminetetraacetic acid (a calcium-chelating agent) in 5 mM phosphate buffer at pH 7.4, which suggests that the enzyme is a calcium-dependent metalloprotease.

Philips' map of Egypt and the Soudan, including the Valley of the Nile, the Red Sea, Abyssinia, Arabia, etc

Kartta kuuluu A. E. Nordenskiöldin kokoelmaan

Changes in red blood cell osmotic fragility induced by total plasma and plasma fractions obtained from rats bearing progressive and regressive variants of the Walker 256 tumor

Two variants (A and B) of the widely employed Walker 256 rat tumor cells are known. When inoculated sc, the A variant produces solid, invasive, highly metastasizing tumors that cause severe systemic effects and death. We have obtained a regressive variant (AR) whose sc growth is slower, resulting in 70-80% regression followed by development of immunity against A and AR variants. Simultaneously with the beginning of tumor regression, a temporary anemia developed (~8 days duration), accompanied by marked splenomegaly (~300%) and changes in red blood cell osmotic fragility, with mean corpuscular fragility increasing from 4.1 to 6.5 g/l NaCl. The possibility was raised that plasma factors associated with the immune response induced these changes. In the present study, we identify and compare the osmotic fragility increasing activity of plasma fractions obtained from A and AR tumor bearers at different stages of tumor development. The results showed that by day 4 compounds precipitating in 60% (NH4)2SO4 and able to increase red blood cell osmotic fragility appeared in the plasma of A and AR tumor bearers. Later, these compounds disappeared from the plasma of A tumor bearers but slightly increased in the plasma of AR tumor bearers. Furthermore, by day 10, compounds precipitating between 60 and 80% (NH4)2SO4 and with similar effects appeared only in plasma of AR tumor bearers. The salt solubility, production kinetics and hemolytic activity of these compounds resemble those of the immunoglobulins. This, together with their preferential increase in rats bearing the AR variant, suggest their association with an immune response against this tumor.

High doses of riboflavin and the elimination of dietary red meat promote the recovery of some motor functions in Parkinson's disease patients

Abnormal riboflavin status in the absence of a dietary deficiency was detected in 31 consecutive outpatients with Parkinson's disease (PD), while the classical determinants of homocysteine levels (B6, folic acid, and B12) were usually within normal limits. In contrast, only 3 of 10 consecutive outpatients with dementia without previous stroke had abnormal riboflavin status. The data for 12 patients who did not complete 6 months of therapy or did not comply with the proposed treatment paradigm were excluded from analysis. Nineteen PD patients (8 males and 11 females, mean age ± SD = 66.2 ± 8.6 years; 3, 3, 2, 5, and 6 patients in Hoehn and Yahr stages I to V) received riboflavin orally (30 mg every 8 h) plus their usual symptomatic medications and all red meat was eliminated from their diet. After 1 month the riboflavin status of the patients was normalized from 106.4 ± 34.9 to 179.2 ± 23 ng/ml (N = 9). Motor capacity was measured by a modification of the scoring system of Hoehn and Yahr, which reports motor capacity as percent. All 19 patients who completed 6 months of treatment showed improved motor capacity during the first three months and most reached a plateau while 5/19 continued to improve in the 3- to 6-month interval. Their average motor capacity increased from 44 to 71% after 6 months, increasing significantly every month compared with their own pretreatment status (P < 0.001, Wilcoxon signed rank test). Discontinuation of riboflavin for several days did not impair motor capacity and yellowish urine was the only side effect observed. The data show that the proposed treatment improves the clinical condition of PD patients. Riboflavin-sensitive mechanisms involved in PD may include glutathione depletion, cumulative mitochondrial DNA mutations, disturbed mitochondrial protein complexes, and abnormal iron metabolism. More studies are required to identify the mechanisms involved.

Melatonin and N-acetyl-serotonin cross the red blood cell membrane and evoke calcium mobilization in malarial parasites

The duration of the intraerythrocytic cycle of Plasmodium is a key factor in the pathogenicity of this parasite. The simultaneous attack of the host red blood cells by the parasites depends on the synchronicity of their development. Unraveling the signals at the basis of this synchronicity represents a challenging biological question and may be very important to develop alternative strategies for therapeutic approaches. Recently, we reported that the synchrony of Plasmodium is modulated by melatonin, a host hormone that is synthesized only during the dark phases. Here we report that N-acetyl-serotonin, a melatonin precursor, also releases Ca2+ from isolated P. chabaudi parasites at micro- and nanomolar concentrations and that the release is blocked by 250 mM luzindole, an antagonist of melatonin receptors, and 20 mM U73122, a phospholipase C inhibitor. On the basis of confocal microscopy, we also report the ability of 0.1 µM melatonin and 0.1 µM N-acetyl-serotonin to cross the red blood cell membrane and to mobilize intracellular calcium in parasites previously loaded with the fluorescent calcium indicator Fluo-3 AM. The present data represent a step forward into the understanding of the signal transduction process in the host-parasite relationship by supporting the idea that the host hormone melatonin and N-acetyl-serotonin generate IP3 and therefore mobilize intracellular Ca2+ in Plasmodium inside red blood cells.

An improved HPLC method for the quantitation of 6-mercaptopurine and its metabolites in red blood cells

A procedure is described for the rapid determination of the intra-erythrocyte concentration of 6-mercaptopurine (6-MP) and its metabolites, 6-thioguanine nucleotides (6-TGN) and 6-methylmercaptopurine (6-MMP). Erythrocytes (8 x 10(8) cells) in 350 µl Hanks solution containing 7.5 mg dithiothreitol were treated with 50 µl 70% perchloric acid. The precipitate was removed by centrifugation (13,000 g) and the supernatant hydrolyzed at 100°C for 45 min. After cooling, 100 µl was analyzed directly by HPLC using a Radialpack Resolve C18 column eluted with methanol-water (7.5:92.5, v/v) containing 100 mM triethylamine. 6-TG, 6-MP and the hydrolysis product of 6-MMP, 4-amino-5-(methylthio)carbonyl imidazole, were monitored at 342, 322 and 303 nm using a Shimadzu SPD-M10A diode array UV detector. The analytes eluted at 5.3, 6.0 and 10.2 min, respectively. The calibration curves were linear (r² > 0.998), and the analytical recoveries were 73.2% for 6-TG, 119.1% for 6-MP and 97.4% for 6-MMP. The intra- and inter-assay variations were highest for 6-MP (9.6 and 14.3%, respectively). The lowest detectable concentrations were 3, 3 and 25 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The quantification limits (coefficients of variation <15%) were 8, 10 and 70 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The method was applied to the analysis of 183 samples from 36 children under chemotherapy for acute lymphoblastic leukemia. The concentrations of the metabolites in the red cells of the patients ranged from 0 to 1934 pmol/8 x 10(8) erythrocytes for 6-TGN, and from 0 to 105.8 and 0 to 45.9 nmol/8 x 10(8) erythrocytes for 6-MP and 6-MMP, respectively. The procedure gave results that were in agreement with those obtained with other methods designed to detect cases of non-compliance with treatment, including patient interviews and medical evaluation, among others, demonstrating its applicability to monitoring the treatment of leukemic children.

The alga Bryothamnion seaforthii contains carbohydrates with antinociceptive activity

Bryothamnion seaforthii, a red alga common to the Northeastern coast of Brazil, was used to prepare the protein fraction F0/60 by ammonium sulfate precipitation. The chromatography of F0/60 on DEAE-Sephadel column resulted in two lectin fractions, PI and PII, which have antinociceptive properties in rodents. We determined the antinociceptive activity of the PII fraction and of a carbohydrate-containing fraction (CF) in mice. The CF was prepared from the dried algae, after digestion with 100 mM sodium acetate, pH 6.0, containing 5 mM cysteine, EDTA and 0.4% papain, at 60ºC. A 10% cetylpyridinium chloride was added to the filtrate, and the precipitate was dissolved with 2 M NaCl:ethanol (100:15, v/v) followed by the carbohydrate precipitation with ethanol. The final precipitate, in acetone, was dried at 25ºC. The PII fraction markedly inhibited acetic acid-induced abdominal writhing after ip administration (control: 27.1 ± 2.20; PII 0.1 mg/kg: 5.5 ± 1.85; 1 mg/kg: 1.6 ± 0.72 writhes/20 min) and after oral administration (control: 32.0 ± 3.32; PII 0.1 mg/kg: 13.1 ± 2.50; 1 mg/kg: 9.4 ± 3.96 writhes/20 min). PII was also effective against both phases of pain induced by 1% formalin (control, ip: 48.2 ± 2.40 and 27.7 ± 2.56 s; PII: 1 mg/kg, ip: 34.3 ± 5.13 and 5.6 ± 2.14 s; control, po: 44.5 ± 3.52 and 25.6 ± 2.39 s; PII 5 mg/kg, po: 26.5 ± 4.67 and 15.3 ± 3.54 s for the 1st and 2nd phases, respectively) and in the hot-plate test. The CF (ip) also displayed significant antinociceptive properties in all tests but at higher doses (1 and 5 mg/kg, ip and po). Thus, CF at the dose of 5 mg/kg significantly inhibited writhes (ip: 7.1 ± 2.47 and po: 14.5 ± 2.40 writhes/20 min) as well as the 1st (po: 19.6 ± 1.74 s) and 2nd (po: 7.1 ± 2.24 s) phases of the formalin test compared to controls ip and po. The antinociceptive effects of both the PII and CF in the formalin and hot-plate tests were prevented at least partially by pretreatment with the opioid receptor antagonist naloxone (2 mg/kg, sc). Moreover, both fractions retained antinociceptive activity in the acetic acid-induced writhing test following heating, a procedure which abolished the hemagglutinating activity of the fraction, presumably due to lectins also present. Finally, both fractions also prolonged the barbiturate-induced sleeping time. These results indicate that carbohydrate molecules present in the PII (26.8% carbohydrate) and CF (21% of the alga dried weight) obtained from B. seaforthii display pronounced antinociceptive activity which is resistant to heat denaturation and is mediated by an opioid mechanism, as indicated by naloxone inhibition.

Activation of a P2Y4-like purinoceptor triggers an increase in cytosolic [Ca2+] in the red blood cells of the lizard Ameiva ameiva (Squamata, Teiidae)

An increasing number of pathophysiological roles for purinoceptors are emerging, some of which have therapeutic potential. Erythrocytes are an important source of purines, which can be released under physiological and physiopathological conditions, acting on purinergic receptors associated with the same cell or with neighboring cells. Few studies have been conducted on lizards, and have been limited to ATP agonist itself. We have previously shown that the red blood cells (RBCs) of the lizard Ameiva ameiva store Ca2+ in the endoplasmic reticulum (ER) and that the purinergic agonist ATP triggers a rapid and transient increase of [Ca2+]c by mobilization of the cation from internal stores. We also reported the ability of the second messenger IP3 to discharge the ER calcium pool of the ER. Here we characterize the purinoceptor present in the cytoplasmic membrane of the RBCs of the lizard Ameiva ameiva by the selective use of ATP analogues and pyrimidine nucleotides. The nucleotides UTP, UDP, GTP, and ATPgammaS triggered a dose-dependent response, while interestingly 2MeSATP, 2ClATP, alpha, ß-ATP, and ADP failed to do so in a 1- to 200-µm con- centration. The EC50 obtained for the compounds tested was 41.77 µM for UTP, 48.11 µM for GTP, 53.11 µM for UDP, and 30.78 µM for ATPgammaS. The present data indicate that the receptor within the RBCs of Ameiva ameiva is a P2Y4-like receptor due to its pharmacological similarity to the mammalian P2Y4 receptor.